Field of the Disclosure
Embodiments of the present invention relate to an organic light emitting display device, and more particularly, to a top emission type organic light emitting display device, and a method of manufacturing the same.
Discussion of the Related Art
An organic light emitting display (OLED) device, which is a self-light emitting display device, has advantages of low power consumption, rapid response speed, high emission efficiency, high luminance and wide viewing angle.
According to the direction of light emitted from an organic light emitting device, the OLED device may be generally classified into a top emission type and a bottom emission type. In the bottom emission type, a circuit device is disposed between an emitting layer and an image displaying surface, which may lower an aperture ratio of the OLED device. In the top emission type, a circuit device is not disposed between an emitting layer and an image displaying surface, thus an aperture ratio may be improved when compared to the bottom emission type.
FIG. 1 is a cross sectional view of a related art top emission type OLED device.
As shown in FIG. 1, a thin film transistor layer (T) including an active layer 11, a gate insulating film 12, a gate electrode 13, an insulating interlayer 14, a source electrode 15, and a drain electrode 16 is provided on a substrate 10, and then a passivation layer 20 and a planarization layer 30 are sequentially provided on the thin film transistor layer (T).
Also, an anode electrode 40 and an auxiliary electrode 50 are provided on the planarization layer 30. The auxiliary electrode 50 is provided to lower a resistance of a cathode electrode 90. In the top emission type, light emitted from an organic emitting layer 80 passes through the cathode electrode 90. In this reason, the cathode electrode 90 is formed of a transparent conductive material, which causes the increase of resistance therein. In order to lower the resistance of the cathode electrode 90, the cathode electrode 90 is connected with the auxiliary electrode 50.
On the anode electrode 40 and the auxiliary electrode 50, a bank 60 is provided to define a pixel region. Also, the organic emitting layer 80 is provided in the pixel region defined by the bank 60.
If the auxiliary electrode 50 is covered by the organic emitting layer 80, an electrical connection between the cathode electrode 90 and the auxiliary electrode 50 becomes difficult. Thus, in order to prevent the auxiliary electrode 50 from being covered by the organic emitting layer 80, a partition 70 is provided on the auxiliary electrode 50. The partition 70 is spaced apart from the bank 60, whereby the auxiliary electrode 50 and the cathode electrode 90 are connected to each other via a space between the partition 70 and the bank 60.
The partition 70 can include a first partition 71 and a second partition 72, in which the partition 70 is formed in a structure of eaves. Thus, according as the organic emitting layer 80 with superior straightness for the properties of process is blocked by the partition 70, it is possible to prevent the organic emitting layer 80 from being permeated into the space between the partition 70 and the bank 60. Meanwhile, the cathode electrode 90 with inferior straightness for the properties of process permeates into the space between the partition 70 and the bank 60, and is then connected to the auxiliary electrode 50.
In the related art top emission type OLED device, the partition 70 is provided to allow an electrical connection between the cathode electrode 90 and the auxiliary electrode 50. Accordingly, an additional mask process for forming the partition 70 is carried out, thereby causing a lower yield.